MUC16 (mucin 16) is a large membrane-bound glycoprotein that serves as both a structural component and a clinically significant biomarker. At the cellular level, MUC16 provides protective and lubricating functions at mucosal surfaces 1. Beyond its normal physiological role, MUC16 is abnormally expressed or mutated in various malignancies, particularly ovarian and pancreatic cancers, where it becomes an important cancer-related biomarker 2. The protein participates in tumor progression through multiple signaling pathways including PI3K/AKT, JAK2/STAT3, and ERK/FBW7/c-Myc mechanisms 2. MUC16 also facilitates immune escape by inhibiting T and NK cells 2. Clinically, elevated serum CA125 (the shed form of MUC16) correlates with disease burden and prognosis in ovarian cancer and reflects congestion and inflammation in heart failure patients 13. MUC16 has emerged as a promising immunotherapy target; neoantigens derived from MUC16 mutations correlate with improved survival in pancreatic cancer patients through enhanced T-cell recognition 4. Multiple therapeutic approaches are in development, including bispecific T-cell engaging antibodies 5, antibody-drug conjugates 6, and site-specific engineered conjugates 7. These advances suggest MUC16 represents a valuable target for both cancer detection and treatment 8.